Control Charts -- Step 4: Defects, Filters and Statistics

Step 4 in the Control Chart Builder is selecting what data to include and exclude. The Defect Management System program gives you three ways to narrow your analysis. Access these options from the tabs for Defects, Filters and Statistics.

Defects

For detailed information on selecting defects, see Defect tab

Filters

The Filter tab permits a specialized selection of data. See Filter Tab

Statistics

Use the Statistics tab to calculate:

• The cost of a part (Standard’s cost per unit).

• The cost for each kind of defect (Defect list).

• Bypass cost to improve speed.

The default is based on the setting in System Administration.

What do the three choices mean?

• Standard’s cost per unit: You associate a cost with a part, e.g., if we make a bad widget, the sunk cost (i.e., the money lost), at this point in the manufacturing process is $5. In that case, the cost is associated with a specific part and put in the standard record for the widget. The cost of the part is established in setup.

• Defect list: You associate a cost with each kind of defect, e.g., scratches cost us $.75 a piece. This method is typically used to track standard repair costs. In that case, the cost is put in the defect list. Each defect was assigned a cost during setup.  Calculations will be based on this value.

• Bypass cost to improve speed: If you don’ t care about cost, it is faster to use this option. Because the system does not have to search each standard for cost information, it runs faster.

Exclude statistical outliers

You may choose whether to include all data in your retrieval or to exclude outliers. Outliers are observations that fall outside normal statistical limits due to specific cause variation. Excluding outliers for special causes may give a better picture of how your process is performing.

After you have completed this step, click on Finish to see the chart or charts you have created.